Most lip-sync issues come from source file quality or model mismatch. This guide covers the most common problems and how to resolve them.
Generate button stays grey
The Generate button only activates when both a source file and a voiceover are selected. If it stays grey, at least one input is empty.
Lips don't sync accurately
Source video quality also matters — shaky footage or a face that moves frequently out of center reduces accuracy. A steady video with a face in the center works best.
Face is not detected
If generation produces no visible lip movement, the model may not have found a usable face in the source. Common causes:
- Multiple faces in the frame
- Face too small or partially out of frame
- Low contrast or very dark footage
Output quality is lower than expected
The default model, Lipsync Labs, is optimized for speed. For better output resolution — up to 4K — switch to Lipsync 2 Pro. If you're starting from a still photo, InfiniteTalk is the only model that accepts image input.
Processing takes longer than expected
Processing time scales with voiceover length. A 30-second voiceover generates faster than a 5-minute one. This is expected behavior — longer audio requires more processing. There's no way to speed it up within the app.